ERF: Heals for 3, likely instantly dies to everything aggro. Sometimes it’s too early to trigger, so you play a vanilla 3/3 for 3.

Shaku: 95% guaranteed to attack = one card. -1 attack for a free card is a deal. Can be combo’d with CB for lethal easily next turn. Worst case scenario, you get a cheap spell to combo with Gadget. Best case: Legendary

It’s not an edwin, or game winning card. It fills the 3-mana spot nicely, which Rogue lacks. (Edwin isn’t really a 3-mana card). A good replacement for Shade of Nax.